Chūnin (中忍, Literally meaning: Middle Ninja, Meaning (Viz): Journeyman Ninja) are ninja who are qualified to guide other ninja and lead missions. Chūnin have reached a level of maturity and ability that primarily consists of leadership skills and tactical prowess. Genin who do not have the skills to become chūnin are weeded out in the chūnin exams. Some of them, like Iruka Umino, Daikoku Funeno and Suzume move on to function as Academy teachers and others, like Shikamaru Nara, serve as team leaders in charge of small teams who need to make decisions and utilise the skills of the shinobi under their command to the maximum effect. Chūnin are typically sent on C-rank or B-rank missions.

To become a chūnin, a genin participates in a large examination, known as the "Chūnin Exams". The only exam seen in the series is a three-stage exam held in Konohagakure. In the NarutoOVA, A Chūnin Exam of Flames! Naruto vs. Konohamaru, Naruto and Konohamaru were participating in the Chūnin Exams held in the Sunagakure. Those who pass the test and become chūnin are eligible to wear an identifying flak jacket that holds ninjutsu scrolls. This vest is not mandatory; instead, some opt for more elaborate clothing like capes and robes.